release/19.x: [LLD] [MinGW] Recognize the -rpath option (#102886)

[llvmbot]

Backport 69f76c7

Requested by: @mstorsjo

[llvmbot]

@alvinhochun What do you think about merging this PR to the release branch?

[llvmbot]

@llvm/pr-subscribers-lld

Author: None (llvmbot)

Changes

Backport 69f76c7

Requested by: @mstorsjo

---

Full diff: https://github.com/llvm/llvm-project/pull/104843.diff

3 Files Affected:

• (modified) lld/MinGW/Driver.cpp (+3)
• (modified) lld/MinGW/Options.td (+3)
• (modified) lld/test/MinGW/driver.test (+6)

diff --git a/lld/MinGW/Driver.cpp b/lld/MinGW/Driver.cpp
index 35fd478a21905e..c7d7b9cfca386f 100644
--- a/lld/MinGW/Driver.cpp
+++ b/lld/MinGW/Driver.cpp
@@ -448,6 +448,9 @@ bool link(ArrayRef<const char *> argsArr, llvm::raw_ostream &stdoutOS,
       add("-errorlimit:" + s);
   }
 
+  if (auto *a = args.getLastArg(OPT_rpath))
+    warn("parameter " + a->getSpelling() + " has no effect on PE/COFF targets");
+
   for (auto *a : args.filtered(OPT_mllvm))
     add("-mllvm:" + StringRef(a->getValue()));
 
diff --git a/lld/MinGW/Options.td b/lld/MinGW/Options.td
index 56f67e3dd96c42..7bd5fb80749da2 100644
--- a/lld/MinGW/Options.td
+++ b/lld/MinGW/Options.td
@@ -243,6 +243,9 @@ defm: EqNoHelp<"sysroot">;
 def: F<"sort-common">;
 def: F<"start-group">;
 
+// Ignored options, that produce warnings
+defm rpath: EqNoHelp<"rpath">;
+
 // Ignore GCC collect2 LTO plugin related options. Note that we don't support
 // GCC LTO, but GCC collect2 passes these options even in non-LTO mode.
 def: J<"plugin-opt=-fresolution=">;
diff --git a/lld/test/MinGW/driver.test b/lld/test/MinGW/driver.test
index cbccd09793c2f0..0dab66b613c774 100644
--- a/lld/test/MinGW/driver.test
+++ b/lld/test/MinGW/driver.test
@@ -446,3 +446,9 @@ RUN: ld.lld -### foo.o -m i386pep --build-id=none 2>&1 | FileCheck -check-prefix
 RUN: ld.lld -### foo.o -m i386pep -s 2>&1 | FileCheck -check-prefix=NO_BUILD_ID %s
 RUN: ld.lld -### foo.o -m i386pep -S 2>&1 | FileCheck -check-prefix=NO_BUILD_ID %s
 NO_BUILD_ID: -build-id:no
+
+RUN: ld.lld -### foo.o -m i386pep -rpath foo 2>&1 | FileCheck -check-prefix=WARN_RPATH %s
+RUN: ld.lld -### foo.o -m i386pep --rpath foo 2>&1 | FileCheck -check-prefix=WARN_RPATH %s
+RUN: ld.lld -### foo.o -m i386pep -rpath=foo 2>&1 | FileCheck -check-prefix=WARN_RPATH %s
+RUN: ld.lld -### foo.o -m i386pep --rpath=foo 2>&1 | FileCheck -check-prefix=WARN_RPATH %s
+WARN_RPATH: warning: parameter -{{-?}}rpath has no effect on PE/COFF targets

[mstorsjo]

@alvinhochun What do you think about merging this PR to the release branch?

I think @cjacek or @MaskRay could comment as well.

Technically, this isn't indeed a fix for any regression, but it's a quite safe fix for improving drop-in compatibility vs GNU tools.

[cjacek]

The commit itself seems quite simple and seems safe on its own. I guess the main worry would be that some build system configure checks may, in theory, now consider it as available and start using a different, potentially unintended, code paths. Still, given that it was the case with GNU tools, that risk seems small.

[mstorsjo]

The commit itself seems quite simple and seems safe on its own. I guess the main worry would be that some build system configure checks may, in theory, now consider it as available and start using a different, potentially unintended, code paths. Still, given that it was the case with GNU tools, that risk seems small.

Yes, I guess in theory, you could have a build system that checks whether -rpath is accepted, and starts adding it if it is. Such cases will now start getting warnings... I'm not aware of any such case though, but it's theoretically possible at least.

[github-actions]

@mstorsjo (or anyone else). If you would like to add a note about this fix in the release notes (completely optional). Please reply to this comment with a one or two sentence description of the fix. When you are done, please add the release:note label to this PR.

[mstorsjo]

Release note:
LLD now recognizes the -rpath option in MinGW mode (instead of erroring out). The option is a no-op, and LLD warns about it when passed.